netcheck.zsh

netcheck() {
  emulate -L zsh
  setopt local_options no_monitor no_notify

  local R=$'\e[0m' B=$'\e[1m' G=$'\e[32m' E=$'\e[31m' D=$'\e[90m'
  local OK="${B}${G}✓${R}" NO="${B}${E}✗${R}" WAIT="${D}…${R}"
  local host=google.com url=http://connectivitycheck.gstatic.com/generate_204

  local dns=$WAIT http=$WAIT dp hp dr hr
  draw(){ print -nr -- $'\r\e[2K'"DNS [$dns] | HTTP [$http]"; }

  { (command -v dig >/dev/null && dig +time=1 +tries=1 $host || getent hosts $host) >/dev/null 2>&1 } & dp=$!
  { curl -fsS --max-time 2 $url >/dev/null 2>&1 } & hp=$!

  draw
  wait $dp; dr=$?; dns=$([ $dr -eq 0 ] && echo $OK || echo $NO); draw
  wait $hp; hr=$?; http=$([ $hr -eq 0 ] && echo $OK || echo $NO); draw; echo

  (( dr==0 && hr==0 ))
}